Viser treff 3706-3725 av 4753

    • The Role of Mineral Assemblages in the Environmental Impact of Cu-Sulfide Deposits: A Case Study from Norway 

      Mun, Yulia; Palinkas, Sabina Strmic; Kullerud, Kåre (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-12)
      Metallic mineral deposits represent natural geochemical anomalies of economically valuable commodities but, at the same time, their weathering may have negative environmental implications. Cu-sulfide mineral deposits have been recognized as deposits with a particularly large environmental footprint. However, different Cu deposits may result in significantly different environmental impacts, mostly ...
    • The role of ocean and atmospheric dynamics in the marine-based collapse of the last Eurasian Ice Sheet 

      Sejrup, Hans Petter; Hjelstuen, Berit Oline Blihovde; Patton, Henry; Esteves, Mariana; Winsborrow, Monica; Rasmussen, Tine Lander; Andreassen, Karin Marie; Hubbard, Alun Lloyd (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-19)
      Information from former ice sheets may provide important context for understanding the response of today’s ice sheets to forcing mechanisms. Here we present a reconstruction of the last deglaciation of marine sectors of the Eurasian Ice Sheet, emphasising how the retreat of the Norwegian Channel and the Barents Sea ice streams led to separation of the British-Irish and Fennoscandian ice sheets at ...
    • The role of oxides in the shallow vesiculation of ascending magmas 

      Burgisser, Alain; Arbaret, Laurent; Martel, Caroline; Forien, Melanie; Colombier, Mathieu (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-01)
      Despite their generally low volume fraction, Fesingle bondTi oxides have the potential to greatly influence the eruptive style because they lower the supersaturation pressure for heterogeneous bubble nucleation. Once nucleated, bubbles respond fast to pressure changes, fostering rapid expansion and explosive behavior. Yet, oxide microlite quantifications are often absent from data of explosive ...
    • The role of safety culture in establishing an effective safety information system in the oil and gas industry. A case study of an onshore facility 

      Wolff, Steffen Hauge (Master thesis; Mastergradsoppgave, 2015-06-01)
      The main purpose of this study was to contribute to understanding of how safety culture affects the performance of safety information systems (SISs). More particularly, to investigate how safety culture can both facilitate and inhibit a SIS to function effectively. The thesis has been carried out as a qualitative, single case study of an onshore facility in the oil and gas industry. Seven ...
    • The role of shelf morphology on storm-bed variability and stratigraphic architecture, Lower Cretaceous, Svalbard 

      Grundvåg, Sten-Andreas; Jelby, Mads Engholm; Olaussen, Snorre; Sliwinska, Kasia (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-13)
      The dominance of isotropic hummocky cross‐stratification, recording deposition solely by oscillatory flows, in many ancient storm‐dominated shoreface–shelf successions is enigmatic. Based on conventional sedimentological investigations, this study shows that storm deposits in three different and stratigraphically separated siliciclastic sediment wedges within the Lower Cretaceous succession in ...
    • Role of subsea permafrost and gas hydrate in postglacial Arctic methane releases 

      Portnov, Aleksei D (Doctoral thesis; Doktorgradsavhandling, 2015-09-18)
      Greenhouse gas methane is contained as gas hydrate, an icy structure, under the seabed in enormous amounts of Arctic regions. West Svalbard continental margin, which we investigated here, is one of these regions. Also, in the Russian Kara Sea the subsea permafrost is acting as a cap for the gas to be released in the future. But continuous expulsions of methane have been already observed in both ...
    • Role of tectonic stress in seepage evolution along the gas hydrate-charged Vestnesa Ridge, Fram Strait 

      Plaza-Faverola, Andreia; Bünz, Stefan; Johnson, Joel E.; Chand, Shyam; Knies, Jochen; Mienert, Jurgen; Franek, Peter (Journal article; Tidsskriftartikkel, 2015-02-03)
    • Role of tectonic stress in seepage evolution along the gas hydrate‐charged Vestnesa Ridge, Fram Strait 

      Plaza-Faverola, Andreia; Bünz, Stefan; Johnson, Joel E; Chand, Shyam; Knies, Jochen; Mienert, Jurgen; Franek, Peter (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-13)
      Methane expulsion from the world ocean floor is a broadly observed phenomenon known to be episodic. Yet the processes that modulate seepage remain elusive. In the Arctic offshore west Svalbard, for instance, seepage at 200–400 m water depth may be explained by ocean temperature‐controlled gas hydrate instabilities at the shelf break, but additional processes are required to explain seepage in ...
    • Role of transfer functions in PSO to select diagnostic attributes for chronic disease prediction: An experimental study 

      Malakar, Samir; Sen, Swaraj; Romanov, Sergei; Kaplun, Dmitrii; Sarkar, Ram (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-22)
      Particle Swarm Optimization (PSO) is a classic and popularly used meta-heuristic algorithm in many reallife optimization problems due to its less computational complexity and simplicity. The binary version of PSO, known as BPSO, is used to solve binary optimization problems, such as feature selection. Like other meta-heuristic optimization techniques designed on the continuous search space, PSO ...
    • Role of zero-point vibrational corrections to carbon hyperfine coupling constants in organic pi radicals 

      Chen, Xiao; Rinkevicius, Zilvinas; Ruud, Kenneth; Ågren, Hans (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      By analyzing a set of organic π radicals, we demonstrate that zero-point vibrational corrections give significant contributions to carbon hyperfine coupling constants, in one case even inducing a sign reversal for the coupling constant. We discuss the implications of these findings for the computational analysis of electron paramagnetic spectra based on hyperfine coupling constants evaluated at the ...
    • Roll motion on small traditional Norwegian fishing vessels 

      Kristiansen, Gøran (Master thesis; Mastergradsoppgave, 2021-08-09)
      Roll motion is one of the six degrees of freedom and is the most difficult to predict, as roll motion is extremely sensitive to the viscous effect and induced flow separation. The smaller fishing vessel fleet commonly operates in almost all weather conditions, and sometimes in remote areas with cold arctic water where rescue can be far away and difficult. The safety of fishers depends on the vessel's ...
    • Room Temperature-Stable Magnesium Electride via Ni(II) Reduction 

      Do, Cuong Dat; Day, Craig S.; Odena, Carlota; Benet-Buchholz, Jordi; Xu, Liang; Foroutan-Nejad, Cina; Hopmann, Kathrin Helen; Martin, Ruben (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-13)
      Herein, we report the synthesis of highly reduced bipyridyl magnesium complexes and the first example of a stable organic magnesium electride supported by quantum mechanical computations and X-ray diffraction. These complexes serve as unconventional homogeneous reductants due to their high solubility, modular redox potentials, and formation of insoluble, non-coordinating byproducts. The applicability ...
    • Root Cause Analysis of fire in waste facilities: A case study of Tromsø municipality 

      Kargar, Marjan (Master thesis; Mastergradsoppgave, 2021-06-01)
      The amount of waste produced in Norway has been increased considerably in the past decades as a result of population and economic growth. Therefore, the role of waste management companies in society has become more important. One of the significant challenges in the waste facilities is the fire that occurs regularly and causes various problems for the waste management companies. Several causes can ...
    • ROPE: Reducing the Omni-kernel Power Expenses 

      Karlberg, Jan-Ove (Master thesis; Mastergradsoppgave, 2014-05-15)
      Over the last decade, power consumption and energy efficiency have arisen as important performance metrics for data center computing systems hosting cloud services. The incentives for reducing power consumption are several, and often span economic, technological, and environmental dimensions. Because of the vast number of computers currently employed in data centers, the economy of scale dictates ...
    • Rossby Wave Changes During the Recent Decades in Mid-Latitude Continents in the Northern Hemisphere 

      Juskenaite, Ieva (Master thesis; Mastergradsoppgave, 2022-06-22)
      Increasing frequency and severity of extreme weather events throughout the recent years is a highly concerning topic. Extreme and unusual weather conditions, such as heat waves, floods and cold spells are causing a major concern for humanity. Agricultural changes, damages in infrastructure and the loss of human lives are some of the extreme weather event consequences, with the most drastic consequences ...
    • Rotational averaging of multiphoton absorption cross sections 

      Friese, Daniel Henrik; Beerepoot, Maarten T. P.; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • RS-HeRR: a rough set-based Hebbian rule reduction neuro-fuzzy system 

      Liu, Feng; Sekh, Arif Ahmed; Quek, Chai; Ng, Geok See; Prasad, Dilip K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-01)
      Interpretabilty is one of the desired characteristics in various classification task. Rule-based system and fuzzy logic can be used for interpretation in classification. The main drawback of rule-based system is that it may contain large complex rules for classification and sometimes it becomes very difficult in interpretation. Rule reduction is also difficult for various reasons. Removing important ...
    • RS-Seismic Processing and Web-Visualization 

      Pedersen, Tom Arne (Master thesis; Mastergradsoppgave, 2014-05-15)
      The University of Tromsø is conducting regular marine seismic acquisition cruises for scientific and educational purposes in the polar regions of the Norwegian Sea and beyond. Leading experts in the field currently employed by the Department of Geology at ui, have found the current seismic visualization tools lacking in several fields. The available seismic software provides a multitude of settings ...
    • Ruoksat. A system for capturing, persisting and presenting the digital footprint of soccer knowledge and expertise 

      Sørensen, Kim-Edgar (Master thesis; Mastergradsoppgave, 2013-06-01)
      There are currently over 27 000 registered soccer teams in Norway. However, even with mandatory coaching licenses, there are still a vast variety of approaches to how training sessions should be planned and executed. Even in top-level professional soccer organizations, the planning of exercises involves a considerable amount of manual labor. The most common approaches include using old-fashioned pen ...
    • Russia's Critical Infrastructure Policy: What do we Know About it? 

      Pursiainen, Christer Henrik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-29)
      The article is an analytical state-of-the-art review of the Russian Federation’s critical infrastructure policy, starting from the 1990s but zooming in on the current situation. The article discusses what does critical infrastructure mean in the Russian context. It explores the country’s threat scenarios in this field, and asks what part is played by cyber security threats in this context. Further, ...